Becker-Posner Blog: The Economics of Capital Punishment--Posner: The recent
execution by the State of California of the multiple murderer Stanley "Tookie"
Williams has brought renewed controversy to the practice of capital
punishment... From an economic standpoint, the principal considerations in
evaluating the issue of retaining capital punishment are the incremental
deterrent effect of executing murderers, the rate of false positives (that is,
execution of the innocent), the cost of capital punishment relative to life
imprisonment without parole (the usual alternative nowadays), the utility that
retributivists and the friends and family members of the murderer's victim ...
derive from execution, and the disutility that fervent opponents of capital
punishment, along with relatives and friends of the defendant, experience. The
utility comparison seems a standoff, and I will ignore it...

Early empirical analysis by Isaac Ehrlich found a substantial incremental
deterrent effect of capital punishment, a finding that coincides with the common
sense of the situation: it is exceedingly rare for a defendant who has a choice
to prefer being executed to being imprisoned for life. Ehrlich's work was
criticized by some economists, but more recent work by economists Hashem
Dezhbakhsh, Paul Rubin, and Joanna Shepherd ... found, in a careful econometric
analysis, that one execution deters 18 murders. Although this ratio may seem
implausible given that the probability of being executed for committing a murder
is less than 1 percent ..., even a 1 percent or one-half of 1 percent
probability of death is hardly trivial; most people would pay a substantial
amount of money to eliminate such a probability.

As for the risk of executing an innocent person, this is exceedingly slight,
especially when a distinction is made between legal and factual innocence. Some
murderers are executed by mistake in the sense that they might have a good legal
defense to being sentenced to death, such as having been prevented from offering
evidence in mitigation of their crime, such as evidence of having grown up in
terrible circumstances... But they are not innocent of murder. The number of
people who are executed for a murder they did not commit appears to be
vanishingly small. ... Although it may seem heartless to say so, the concern
with mistaken execution seems exaggerated...

[T]here is an economic argument for speeding up the imposition of the death
penalty...; the gain in deterrence and reduction in cost are likely to exceed
the increase in the very slight probability of executing a factually innocent
person. What is more, by allocating more resources to the litigation of capital
cases, the error rate could be kept at its present very low level even though
delay in execution was reduced. However, even with the existing, excessive,
delay, the recent evidence concerning the deterrent effect of capital punishment
provides strong support for resisting the abolition movement.

A final consideration returns me to the case of "Tookie" Williams. The major
argument made for clemency was that he had reformed in prison and ... had become
an influential critic of the type of gang violence in which he had engaged.
Should the argument have prevailed? On the one hand, if murderers know that by
"reforming" on death row they will have a good shot at clemency, the deterrent
effect of the death penalty will be reduced. On the other hand, the type of
advocacy in which Williams engaged probably had some social value, ...clemency
is the currency in which such activities are compensated and therefore
encouraged. Presumably grants of clemency on such a basis should be rare, since
there probably are rapidly diminishing social returns to death-row advocacy,
along with diminished deterrence as a result of fewer executions. For the more
murderers under sentence of death there are who publicly denounce murder and
other criminality, the less credibility the denunciations have.

Becker-Posner Blog: The Economics of Capital Punishment--Posner: The recent
execution by the State of California of the multiple murderer Stanley "Tookie"
Williams has brought renewed controversy to the practice of capital
punishment... From an economic standpoint, the principal considerations in
evaluating the issue of retaining capital punishment are the incremental
deterrent effect of executing murderers, the rate of false positives (that is,
execution of the innocent), the cost of capital punishment relative to life
imprisonment without parole (the usual alternative nowadays), the utility that
retributivists and the friends and family members of the murderer's victim ...
derive from execution, and the disutility that fervent opponents of capital
punishment, along with relatives and friends of the defendant, experience. The
utility comparison seems a standoff, and I will ignore it...